import { onBeforeUnmount, onMounted, watchEffect } from "vue";
import type { ComputedRef, Ref } from "vue";

export const useDraggable = (targetRef: Ref<HTMLElement | undefined>, dragRef: Ref<HTMLElement | undefined>, draggable: any) => {
  let transform = {
    offsetX: 0,
    offsetY: 0
  };

  const onMousedown = (e: MouseEvent) => {
    const downX = e.clientX;
    const downY = e.clientY;
    const { offsetX, offsetY } = transform;

    const targetRect = targetRef.value!.getBoundingClientRect();
    const targetLeft = targetRect.left;
    const targetTop = targetRect.top;
    const targetWidth = targetRect.width;
    const targetHeight = targetRect.height;

    const clientWidth = document.documentElement.clientWidth;
    const clientHeight = document.documentElement.clientHeight;

    const minLeft = -targetLeft + offsetX;
    const minTop = -targetTop + offsetY;
    const maxLeft = clientWidth - targetLeft - targetWidth + offsetX;
    const maxTop = clientHeight - targetTop - targetHeight + offsetY;

    const onMousemove = (e: MouseEvent) => {
      const moveX = Math.min(Math.max(offsetX + e.clientX - downX, minLeft), maxLeft);
      const moveY = Math.min(Math.max(offsetY + e.clientY - downY, minTop), maxTop);

      transform = {
        offsetX: moveX,
        offsetY: moveY
      };
      targetRef.value!.style.transform = `translate(${moveX}px, ${moveY}px)`;
    };

    const onMouseup = () => {
      document.removeEventListener("mousemove", onMousemove);
      document.removeEventListener("mouseup", onMouseup);
    };

    document.addEventListener("mousemove", onMousemove);
    document.addEventListener("mouseup", onMouseup);
  };

  const onDraggable = () => {
    if (dragRef.value && targetRef.value) {
      dragRef.value.addEventListener("mousedown", onMousedown);
    }
  };

  const offDraggable = () => {
    if (dragRef.value && targetRef.value) {
      dragRef.value.removeEventListener("mousedown", onMousedown);
    }
  };

  onMounted(() => {
    watchEffect(() => {
      if (draggable) {
        onDraggable();
      } else {
        offDraggable();
      }
    });
  });

  onBeforeUnmount(() => {
    offDraggable();
  });
};
